As fans of Google's Android mobile software well know, each new version is named after a sugary treat, such as Gingerbread or Honeycomb. Android is about to get even sweeter with Ice Cream Sandwich - a smooth, feature-rich operating system that will run first on the delectable Samsung Galaxy Nexus smartphone.

The combination of Google's software and Samsung's hardware makes the Galaxy Nexus one of the best candidates to compete with Apple's latest iPhone, though its price is steep. It will be available Thursday in the US for $300 with a two-year Verizon Wireless contract.

Like the previous phone in the Nexus line, the Nexus S, the Galaxy Nexus was jointly developed by Google Inc. and Samsung Electronics Co. It features a slim frame with a large, curved glass screen that's comfortable for chatting with friends and excellent for watching videos. There are 32 gigabytes of built-in storage space on the Verizon version of the phone, but no external slot for a microSD memory card.

The screen, a pocket-busting 4.65 inches at the diagonal, makes the iPhone's 3.5-inches look diminutive. And despite the size, the Galaxy Nexus manages to weigh just 4.8 ounces, slightly less than Apple's offering.

On it, videos and Web pages looked crisp and bright, with rich colors. I started watching a video during testing - an HD copy of "The Help" that I rented from Google's Android Market - and had to force myself to break away to test other features of the device.

With the latest version of Android under the hood, the Galaxy Nexus is packed with new and improved features. Many of them are great; others are simply great in theory.

Overall, the software looks fresher and less cluttered. The virtual "buttons" that usually sit at the bottom of the screen have been redesigned. There's still a "home" and a "back" button, but no "menu" button to pull up various options within an app. Instead, there's now a "recent apps" button that shows what you've been doing lately on the phone.

Another neat change: The buttons are completely virtual, so they change directions when you flip the phone sideways and disappear when you're viewing photos or videos.

Other changes to Android include an overhaul of its virtual keyboard, meant to make it easier to type without messing up - something I've always had trouble with on the stock Android keyboard. I was often able to type more accurately than in the past, but sometimes still ended up with unintended words in my messages.

The Android browser and Gmail are updated, too. Gmail's new functions include the ability to search emails while offline, while the browser is zippier and has a "request desktop" option so you can check out webpages in their non-truncated desktop version.

One new feature that falls into the "great in theory" category is Face Unlock, which uses facial-recognition technology to unlock the phone from standby mode. To set it up, you take a picture of your face with the phone. Then, all you have to do to unlock the phone is stare at the screen after you press the power button.

Most of the time it didn't work, though, probably because the phone couldn't recognise my face from certain angles. I was also able to fool it by holding up a shot of my face on an iPhone. So much for security.

Ice Cream Sandwich also has Android Beam, which lets you share such content as a Web page, map or video between two Android phones by bringing the backs of the phones close together. It only works with phones that have this Android software and near-field communication technology, though, so unless you and your friend both buy the Galaxy Nexus you'll be out of luck at launch.

More immediately useful was the phone's 5-megapixel camera, which is the snappiest I've seen on any Android phone. There was almost no shutter lag between shots, even when I had just turned the camera on.

Still, I would have preferred a higher-resolution sensor - 8-megapixel cameras are quickly becoming common on smartphones. In addition, photos I took could have been brighter, though this can be improved on somewhat by using some of the available editing options, including numerous color filters and adjustable contrast options.

Like the iPhone 4S and some other high-end smartphones, the Galaxy Nexus can record high-definition videos in 1080p - the best resolution you can get on a consumer camera. I had some fun taking sunset videos with a time-lapse feature, and there are some goofy filming effects to play around with, too.

And yes, you can make calls on the Galaxy Nexus. Its thin body and curved screen make it comfortable to hold against your ear, and calls generally sounded good.

Sadly, high-speed networks guzzle battery power like a milkshake, so I wasn't able to spend a ton of time using the device on a single battery charge.

The phone Google loaned me to test was a version that works with AT&T or T-Mobile, so I couldn't test its speed or battery life with the carrier actually selling it in the US, Verizon, or with its high-speed 4G network.

Using both T-Mobile's standard 3G and speedier HSPA+ networks, at least, I got about three hours and 15 minutes out of the Galaxy Nexus for surfing the Web, streaming a movie, sending instant messages, chatting on the phone and other activities. The phone got quite warm with all this use. Over Verizon Wireless' 4G LTE network, it's possible that the phone's battery would drain even faster if you're doing a lot of downloading.

Another bummer: Verizon is blocking the Galaxy Nexus from supporting Google Wallet, which is supposed to allow the phone to be used to buy items in some stores by tapping it to payment terminals.